A variety of coatings for paper have been developed to impart many different properties to the paper. These properties can include color, stiffness, receptivity to indicia, water resistance, bleedthrough resistance, release from pressure sensitive adhesives, etc.
Mertens, U.S. Pat. No. 5,154,962 describes a coating which comprises copolymers of (A) free radically polymerizable vinyl monomer, (B) polar monomer in a sufficient amount to impart a hydrated glass transitition temperature (Tg) of -15 degrees C. to 35 degrees C. and a difference of at least 20 degrees C. between the hydrated and actual Tgs, and (C) siloxane-based polymer of a type and in an amount that will impart a satisfactory release value, The coating provides a substrate with a number of properties including the ability to be effectively written on with solvent and water-based inks, the indicia remaining firmly bonded and resistant to smearing. The coating also provides bleedthrough resistance to these inks. This coating, however, provides such good release properties that repositionable pressure sensitive adhesives do not adhere to it. For example, Post-it.TM. Notes, and Post-it.TM. Tape Flags available from Minnesota Mining and Manufacturing Company ("3M") of St. Paul, Minn., which have a repositionable pressure sensitive adhesive thereon, either immediately or after a very short period of time, fall off of a vertically positioned substrate having the Mertens' coating thereon.
Thus there exists a need for a coating demonstrating ink receptivity and bleedthrough resistance, to which a repositionable pressure sensitive adhesive note can effectively adhere.